Conveyer system



March 12, 1940. N. H. PREBLE CONVEYER SYSTEM Filed May 14, 1936 4 Sheets-Sheet l INVENTOR.

NORMA/v H. PEBBLE ATTORNEY.

March 12, 1940. H PREBLE 2,193,076

- CONVEYER SYSTEM Filed May 14, 1936 4 Sheets-Sheet 2 III 'IIIIIIIIII INVENTOR. N 4 BY NORMA/V H. Pi'fi" ATTORNEY.

March 12, 1940. j 7 2,193,076

CONVEYER SYSTEM.v

Filed May 14, 1936 4 Sheets-Sheet 3 INVENTOR.

IV EMA/V A. P142515 ATTORNEY.

March 12, 1940. R L 2,193,076

CONVEYER SYSTEM Filed May 14, 1956' 4 Sheets-Sheet 4 INVENT OR.

ATTORNEY.

Patented Mar. 12, 1940 UNITED STATES PATENT OFFICE CONVEYER SYSTEM.

Norman Preble, Grosse Pointe, Mich., assignor to Jervis B. Webb Company, Detroit, Mich; a. corporation of Michigan Application May 14, 1936; Serial N... 379,715

9 Claims.

problem in conveyer construction. This tendency to surge may result from many different causes often dificult to both determination and remedy. Developments in. the conveyer art tion and have enabled the use of installations of great length to operate with a uniformity of travel entirely practical for general use. The provision of a plurality of drives automatically 2O responsive to change in load along the line of travel and also automatically cooperating to maintain a uniform rate of travel forthe entire conveyer has been a major contribution in this regard. However where the requirements are 25 very rigid with respect to the necessity for eliminating vibration or surge, such as are met with for a mold conveyer, further improvement is essential.

It is therefore a majorobject of the present 30 invention to provide a conveyer system suitable for use in installations where steady and vibrationless operation is a primary requirement.

. More specifically it is an object of the present invention to provide a conveyer with tracks ade 35 quately supported, preferably on a floor, and with this rigid and substantially level track system as a foundation to provide load carrying and driving units acting in combination to effect an even and steady motion which will satisfy most. exacting 40 requirements.

In carrying out the above it isa further object to provide a main conveyingchain, for operation parallel with the aforementioned track, having guide provision at curves in the line of travel 45 in the form of a plurality of guide rollers located tangent to the desired path. A roller bearing curve with a minimum of friction is thereby provided', but in addition the positive guiding of the chain is assured by provisionof a unique shape. 50 of the rollers at the curves which insures hold-' trucks which support the chain and a pallet or This invention relates to conveyers and has the curves in the line of travel, in combination with the aforementionedguide means, a spring take-up mechanism whereby the driving chain is kept uniformly taut but nevertheless allowing enough resilience to prevent roughness of-operation which might otherwise result with a chain held taut by a rigid support.

-It is a further object to provide a conveyer system ofsuch construction as tomore perfectly maintain an even and steady predetermined rate of travel. 1

Further toprovide for smoothness of operation, it is an important object to so construct the load carrying units operating upon the tracks that the wheeled trucks thereof are connected to theconveying chain and the conveyed platforms in such manner thatthe wheels of the trucks will always be free to follow smoothly a, curve in the line of travel without jarring the conveyed platforms or without exerting any material twisting action tending to bind the chain.

The above and other objects of the invention will appear more fully from the following more detailed description and by reference to the. ac.- companying drawings forming a part hereof and Wherein-- I i Fig. lis a general plan view of asatisfactory .l practical example of a conveyer assembly constructed in accordance with the principles of the present invention showing apart of the endless one turn in the. conveyers line of travel;

Fig. 2 is an enlarged plan showing two of the carrying platform which forms one conveyer carrying unit. The figure shows the trucks in position for operation on a curved portion of the track; p r

Fig. 3 is a transverse section on the line 3-p-3 of Fig. 2 and shows the connection between the 1 chain and a platform supporting truck;

Fig. 4 is a vertical section on the line 44 of Fig. 3 and also shows the connection between the chain and a truck;

Fig. 5 is a planview'of one of the curve sections showing the spring take-up and the connection of the curve section to the straight section of the track, also the rollers for guiding the driving chain on the curve; j

Fig. 6 is a vertical section on the line 6-6 of Fig. 5; r I

Fig. '7 is a vertical section on the line 1-1 of Fig.

' Fig. ,8 is asection on theline 88 ofFig. 5

and shows the location of the guiding roller between the tracks at a turn in the conveyer travel; Fig. 9 shows a longitudinal sectional view on the line 99 of Fig. 1 of one of the caterpillar driving curve units which is supported in a pit below the tracks.

Fig. 10 is a section on line [0-40 of Fig. 1 and shows an end view of the driving unit, the longitudinal View of which is shown in Fig. 9 and particularly shows the tracks supporting the driving unit frame.

Referring to Fig. 1 there is shown a general view of a conveyer installation with an endless track system, which, as indicated'by the sectional representation, might be of considerable length and follow any desired path of travel reduired by the layout of the manufacturing establishment in which it is used. @nly one driving unit 2i! is shown in Fig. l, but it is to be understood that a plurality of such units located at various points in the line of travel is intended to be used, the number depending upon the length of the system and the conditions of the installation.

In general the system shown in Fig. 1 comprises tracks 2:l22 upon which two-wheeled trucks 23 (see Fig. 2) are operated, said trucks being'driven from. amain conveying chain 24 located between the tracks, the chain in turn being driven by the aforementioned driving units so. Each pair of trucks 23' supports a pallet or platform 25 for carrying the loads tobe conveyed. The trucks 23, by their connection between the tracks with the driving chain; also serve as a means of support for the said chain. On straight sections. ofthe conveyer pathno other support orguide for the chain is required as the trucks and their supporting tracks will hold the chain in proper alignment. However, at curves in the line or travel the trucks and tracks will no longer be adequate to hold the chain in the desired path, therefore chainguide rollers are provided to engage the chain inside of the On the 180 curves a spring take-up" is incorporatedwith the guide roller unit inthe form of a platform shown at 2B in Fig. I. Said platform unit with the curved track section and roller guide carried thereby is mounted for limited longitudinal movement relative to the adjacent straight track sections underthe control of a plurality of springs thereby providing for take-up of slack in thechain as well as affording a resilience for the chaindrive essential for smooth operation.

The several cooperating units of the system shown assembled in Fig. l have for clarity been grouped for more detailed description under subheadings as follows:

Load carrying units (Figs. 2, 3 and 4).

spring take-up, slipjoints and guide rollers (Figs. 5, 6, 7 and 8).

Driving units (Figs. 9v and 10) Operation.

Load carrying unit shaft 3! upon which are mounted conventional.

flanged wheels; 32 properly spaced to operate on the double track system. On the main shaftporting structure made up from standard struc tural shapes or castings such as a pair of angles 33 welded or otherwise suitably secured to the shaft 3%, one angle 33 being located just inside each flanged wheel 32. A second pair of angles 3 are symmetrically spaced nearer the center of said shaft, the supports thus formed by angle pairs. 33 and 3 being bridged and secured together by a plate 36. As shown best in Fig. 2 each structural angle member 33 extends a material distance to front and to rear of the shaft 3| and near each end of said angle member 33 there is mounted a so-called thrust washer 35, there being four such washers on each truck unit. These washers 35 are of material area and serve as supporting pads for the pallet or platform 25 while allowing the surfaces of washers 35 to slide on the under surface of said pallet when required in turning, as will later more fully appear. The means to secure each truck 23 to the conveying chain. 2d, connects to the central portion of the shaft 3'! between the downwardly projecting angles 34 by a loose fitting tube 3'! of suflicient length to form a suitable bearing. Welded or otherwise suitably secured to the tube 31 is a downwardly projecting plate 3B having a plate 39 secured at its lower end of construction suit able for effecting. a connection to a link of the conveying chain 24-, specifically shown as connecting plate 39, to threaded projections of iilby nuts and washers ll, 42.

The above detailed construction provides truck units 23 spaced at definite intervals along the conveyer tracks and connected to conveying chain 24!; Provision is made to secure a pallet or carry ing platform 25 on each pair of trucks 23 by pins M each of whichfits in a hole it located centrally between the wheels on each truck, said pins also being, fixed and welded in holes provided in blocks 48: suitably secured to the underside of pallet. 25-. The pallet. 25 is preferably made up of a. flat plate 69 forming the top, with suitable reinforcing angles '50; although various forms of construction might be employed.

It is noted that each truck 23 supporting an end of a pallet 25.is secured toa link of chain 24 and also each' truck 23 has fredom of movement around the center of pin M as an axis. fore when the assembly as shown in Fig. 2, en-

counters a curve in the track and the chain 24 is guided around. said curve the turning of the chain link will also turn the truck 23 about pin M, the surface. of washers 35 sliding on thesmooth under surface of plate 419 of pallet 25. With the chain properly guided in a manner to be later described, it is apparent that the trucks 23 will beturned by the linkof thechain to which each is attached and. if the chain is so guided that the link is kept substantially tangent to the curve being turned then the truck wheels 32 will turn the curve smoothly without binding the wheel flanges on the curved tracks.

Spring take up, slip joints, and guide rollers As shown in Figs. 5, 6, 7 and 8, there is provided a spring. take-up at certain of the turns in the line of travel of the conveyer. To provide for this take-up the entire curve of the track together with a roller turn chain guide are mounted upon a platform as. The curved sections of. the track F El, 621 are provided at their ends with sliding joints 63;. 64,, the location of 'the joints being at a.

point before'the startisof the. curve so that movement of the platform in a direction parallel-with the straight section of the tracks will effect a Theretightening of the chain. The mounting of the platform-for the longitudinal movement islprovided for by a construction locatedina pit- 65.

below the floor line, a cross sectional view of the pit being shown in Figs. 6 and 7-..To carry out this purpose the platform 60 is mounted upon a plurality of rollers 66 supported belowthe platform 68 on suitable channel members 61,168, two such units being shown dotted in the plan view of Fig.

5. At the bottom of the pit, as'shown in Fig. 7, track members 69 are suitably secured to the bottom of the pit. It is apparent that with this construction the platform 550 is mounted formovement to the right or the left, asshown in Fig. 5,

to slide the track slip joints 63 and 64 to tighten or slacken the chain 24. Slip joints 63, 64 are constructed by cutting away complemental halves of the joined ends of the track as shown.

To keep the platform properly located and to prevent the transverse twisting-thereof by the driving load on the chain, suitable rollers 14 are secured to the structural members under the platform 65 andoperate against metal angles 15 provided at the edge of the pit, all of which is shown best in Fig. '7. t

For the purpose of guiding the conveying chain 24' around the curve a roller turn comprising a plurality of rollers located on the inside of the curve, as shown in Fig. 5, is provided. The periphery of each of these rollers is located tangent the curve to be followed by the driving chain. A detail view of the support for one of these rollers -is shown in Fig. 8, and it is therein shown that {a bracket Si is built up on the track 62 so disposed as to locate the roller 86 for rotation on a suitable pin 82. The roller 80 has a shape such that the conveying chainZA will be prevented from slipping thereon, such as annular projec+ tions 83 and 34 as shown in Fig.9. It will be noted that projections 83, 84 are beveled to such shape and are so located that a substantially V-shaped guide is provided at the center of the roller thus forming a guide effective for the closed links of the chain. Furthermore, the outer edges of the projections 83, 84 are so located that they will fit between the open links of the chain thereby completing a positive guide for the chain regardless of the portion thereof in contact with the roller.

The platform 60 is held in place and chain tension maintained by a plurality of spring connections between the pit and transverse members 81 designated generally as 88 and made up of a bolt 89 having its end secured to the pit by any suitable means and projecting through one of the half of the platform 60, it, being understood that.

the unit is symmetrical.

Driving unit One or more driving units 20 are provided to insure adequate drive, depending upon the length of the conveyer system. Each of these units, as shown in Figs. 1, 9 and 10, are so constructed as to be below the tracks 2 I, 22, a pit I ID of sufiicient depth to suspend a carrying frame I I I beingprovided. On this frame themotor H2, speed changing unit H3 and gear box I I4 aremounted. The frame itself. is supported on two tracks H5 and H6 near the top of the pit, as shown best in Fig. 10. There is provided cross shafts H1, H8 projecting outside the frame, the ends thereof being provided with rollers H9 which rollers operate upon the tracks I I5, H6, thereby effecting a support of the unit for limited longitudinal movement to the right and left, as seen in Fig. 9. Limiting this movement are springs I20 against which the entire frame reacts when driving against the main conveying chain, as will later appear more fully- I Continuing with the description of the driving means on the frame I I I, a gear IZI on the output shaft of the gear box II is meshed with a larger gear. I22 which drives the shaft 123 projecting upwardly through suitable bearings I24..

The end of the shaft I23 has secured thereto a sprocket wheel I25. To provideanother sprocket to complete a caterpillar drive, a shaft I26 is mounted for rotation in suitable bearing l2? and of the caterpillar chain with the driving chain is of the type shown in a copending application Serial No. 52,804. Unique to the present construction, however, as shown at ISL in Figs. 9

and 10, one of the tracks 22 is partially cut away and the caterpillar drive placed at a proper height to mesh with the conveying chain 2t midsuch location (see Fig. 1) that the reaction of By a the drive is taken by the springs I20. mechanism, which is not shown andwhich forms no part of the present invention, the speed changing unit H3 is actuated by the aforementioned longitudinal movement of the frame, to compensate for change in driving load between the several driving units.

Operation As previously mentioned, this conveyer system is adapted for use where steady operation is a primary requirement. The tracks located on the floor form a steady foundation for the system and the two wheeled trucks, each of which is individually connected with the conveying chainoperating between the tracks, makes up a compact close-coupled unit. In fact, the trucks in reality are appendages of the chain system following it positively and also supporting said chain on the tracks with the result of substantially eliminating intermittent and jerky motion to be expected when a series of truck units is pulled from a single chain connection. unity of construction is followed out further when pallets 25 are placed on the trucks 23, thus connecting together a pair of the trucks 23 and providing a carrying platform relative- This l y close to the tracks and the conveying chain. I It is also noted that-the driving force exerted by the driving units is not materially offset below the plane of the tracks. The result is, in effect, a platformmounted upon a moving chain, all solidly supported and rolling upon a track exceptionally free from vibration.

When a load carrying unit, as shown in Fig. 2, rounds a curve the line of travel the trucks 2%, turn about pins 51, whichsecu-re the ends of said pallet 25 to said trucks,-the smooth under surfaceof the pallet allowing the washers 35 to slide thereon, Meanwhile the chain 24 follows the curve defined by the guide rollers. 8d (see 5), the chain being guided in such manner on the tracks which was objectionable in'prior constructions. Considering the connection between the truck and chain, as shown in Figs. 3

and 4, it will be apparent .on consideration that any variation from a true tangent position of a v chain link to which a truck 23 is attached would cause a tendency to bindthe wheels on the curve by the turning effect of the chain, this tendency being minimized in the guide roller construction employed. As a further refinement, however, a special construction is employed wherein tube 37 is given a substantial clearance on shaft 3| as shown in Figs. 3 and 4, thereby eliminating any binding tendency which still remains. I It is also noted that clearance is allowed at the ends of tube 37 between said tube and the adjacent pair of angles 34, Both the above clearances, as above explained, allow a limited movement of tube 31 on shaftdi to permit compensation for slight variation in chain operation thereby eliminating any binding tendency which still remains and which would'otherwise produce objectionable vibrations. This clearance is an important feature of the construction contributing to produce the desired result of smooth operation.

The spring take-up construction shown in Figs. 1, 5, 6 and '7 results in holding the chain to the tension exerted by the spring mountings 88 which tend to move the entire platform fill toward the left as shown in Figs. 1 and 5. Such a spring. take-up keeps the chain properly taut and also serves to damp out vibrations which would otherwise be transmitted through the chain. Smooth operation on the curves is further assured by the positive guide for both open and closed links of the chain by the shape of guide rollers 80 which provide a V-shaped guide at the center of each roller for the closed links of the chain and provide also a projection on each roller applied to a specific installation, it is understood that certain variations and modifications may be employed without departing from the fundamental principles as indicated by the scope of the following claims.

'I claimi 1. In a conveyor system, a track havmg straight and'curved sections, a conveying chain mounted for operation parallel with said track, said chain having link sections of varying shape, roller guides defining a path for said chain parallel with a; curved section of said track, a projection pattern on the circumference of said rollers so formed that a guide for one section of said chain is efiected in the central portion of said projection pattern and a guide for another section of said chain is effected by the outer edges of said projection pattern.

2. In a conveyor, a track, a load carrying. unit for operation on said track comprising a pair of wheeled trucks each having an axle, a platform having a smooth under surface supported on said. trucks, a pair of swivel connections between said platform and said trucks located centrally and substantially in a vertical plane through the axle of each of said trucks, thrust washers projecting upwardly from said trucks spaced outwardly from and around said swivel connections and contacting the smooth under surface of said plat form thereby allowing relative sliding movement betweens'aid platform and the upwardly projecting washers on said trucks to allow pivotal movement of said trucks about said swivel connections. 3'. Ina conveyenaconveying chain, a guide for defining the path at a curve in the line of travel comprising, a plurality of rollers mounted inside said curve and tangent to the desired path of travel, an annular projection formed on each of said rollers forming a V-shaped guide at its center for the closed links of the conveying chain and said projection being of a width to fit into the open links of said chain.

4. In a conveyor, a conveying chain, a plurality of wheeled trucks, a plurality of load carrying platforms one supported on each pair of said trucks, and connections from each of said trucks to said conveying chain, and swivel'connections between each truck and its platform located in substantial vertical alignment with said chain connections.

5. In a convcyer, a plurality of wheeled trucks, axles for said trucks, a load carrying platform supported by each pair of said trucks, a swivel connection between said trucks and platform located cent-rally of each of said trucks and in a vertical plane through the axle of each of said truck's, and a plurality of fiat supports on each of said trucks symmetrically spaced about said swivel connection for supporting said platform in a horizontal plane while permitting movement between said truck and platform about said swivel; v

6; In a conveyor, a conveying chain, a plurality of wheeled trucks, axles for said trucks, a plurality of load carrying platforms one supported on each pair of said trucks, and connections from each of said truck axles to said conveying' chain forming the sole means of vertical support for said chain.

'7. In a conveyer, a conveying chain, a plurality of wheeled trucks, a load carrying platform supported by each pair of said trucks, a swivel connection located centrally of each of said trucks securing said platforms on-said trucks, and a connection from each of said trucks to said chain located insubstantially vertical alignment with said swivel connection.

8-. Ina-conveyor, a conveying chain, a plurality Gil of wheeled trucks. a plurality of load carrying for a curved section of said track mounted for limited movement parallel with a straight section of said track, roller guides for said conveying chain mounted on said support and located inside a curve parallel with said track with their peripheries tangent to said curve, adjustable resilient means for fixing the location of said support with a limited freedom of resilient movement thereby to provide for adjusting the tension on said chain and to assure smooth operation thereof.

NORMAN H. PREBLE. 

